Hydrothermal Vents Found in the Icy Depths of the Remote South Sandwich Islands 

An Ocean Census Flagship expedition and GoSouth team of scientists found suspected new species, discovered one of the island chain’s shallowest hydrothermal vents, and explored the deepest trench in the Southern Ocean. 

Palo Alto, CA, USA — An international team of scientists on a recent 35-day deep-sea expedition to one of the most remote island chains in the world observed thriving polar ecosystems, discovered new hydrothermal vents, coral gardens, and many suspected new species. The Ocean Census Flagship expedition aboard Schmidt Ocean Institute’s research vessel Falkor (too) explored the South Sandwich Islands, including one of the coldest and most isolated submarine trenches on the planet, and also found evidence of explosive volcanism. This was the same expedition that filmed the first confirmed sighting of a juvenile colossal squid.

The expedition was part of the Nippon Foundation–Nekton Ocean Census program, the world’s largest initiative to accelerate the discovery of ocean life. The Ocean Census scientists led the species discovery efforts, uncovering a wide range of potentially new marine life — including corals, sponges, snails, sea urchins, benthic ctenophores, and sea stars. The exact number of new species will be announced later this year following an Ocean Census workshop, where taxonomic experts will formally assess and catalog the findings. The GoSouth team — a collaboration between the University of Plymouth (UK), GEOMAR (Germany), and the British Antarctic Survey (UK) — investigated the effects of geohazards, including tsunamis, volcanoes, and earthquakes.

“This expedition has given us a glimpse into one of the most remote and biologically rich parts of our ocean. This is exactly why the Ocean Census exists — to accelerate our understanding of ocean life before it’s too late,” said Dr. Michelle Taylor, head of science and expedition principal investigator at the Ocean Census, and senior lecturer at the University of Essex. “The 35 days at sea were an exciting rollercoaster of scientific discovery; the implications of which will be felt for many years to come as discoveries filter into management action.”

Mother Nature threw everything she had at the expedition, said Taylor, including a subsea earthquake, tropical storm force winds with hurricane-level gusts, eight-meter (26-foot) waves, and icebergs to navigate.

Located in the South Atlantic, the South Sandwich Islands are part of a rich mosaic of geologic features such as hadal zone trenches, underwater volcanoes, and spreading centers — features created by tectonic forces that have supported the evolution of species found nowhere else on the planet. It took eight days for the research vessel to travel to the islands from the port of Punta Arenas, Chile.

The GoSouth team, led by Co-Chief Scientist Dr. Jenny Gales, discovered two pockmarks in the mapping data of an underwater caldera — a bowl-shaped depression in the seafloor, left after a volcano erupts. Pockmarks can indicate hydrothermal activity. Using a “nested” approach, the team deployed Schmidt Ocean Institute’s remotely operated vehicle, SuBastian to map the pockmarks at a higher resolution and confirm the presence of vents.

The larger pockmark contained three hydrothermal vents, and the smaller contained one. Located at 700 meters depth (nearly 2300 feet), they are one of the shallowest hydrothermal vents to have been discovered near the South Sandwich Islands, and the only ones to be explored using a remotely operated vehicle. The tallest vent chimney was four meters (13 feet), making it about as tall as a basketball hoop. Each vent was covered with an array of life dependent on chemosynthesis, including sea snails and barnacles. Thriving coral gardens and large sponges were found in close proximity to the vents — an unusual observation, said Taylor.

“Discovering these hydrothermal vents was a magical moment, as they have never been seen here before,” said Gales, an associate professor in Ocean Exploration at the University of Plymouth (UK). “It’s an incredible discovery that provides valuable insights into the area’s tectonic activity. Making such a discovery is rare. It highlights the importance of ocean exploration and seafloor mapping.”

In addition to the vents, other notable observations during the expedition included:

• In the trench, scientists found snailfish eggs that had been laid on a black coral, as well as a potential new sea cucumber species;
• large pumice blocks, indicating that the South Sandwich Islands are capable of explosive volcanism; 
• a vibrant coral garden located west of Saunders Island at a depth of 120 meters (394 feet); 
• Capturing the first footage of Akarotaxis aff. gouldae, a species of dragonfish that was discovered two years ago.

“The challenging ocean and weather conditions and the isolated location of the South Sandwich Islands capture the imagination of the boldest explorers — often the closest humans to the vessel were on the International Space Station,” said Schmidt Ocean Institute’s Executive Director, Dr. Jyotika Virmani. “We are proud to have collaborated with Ocean Census in their mission to advance the discovery of marine life and GoSouth in their quest to better understand the geological nature of this dynamic corner of the world.” 

Image Credit: Jialing Cai / The Nippon Foundation – Nekton Ocean Census / Schmidt Ocean Institute

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About the Organizations:

April 24th was Massachusetts Right Whale Day. A vertical puff of water vapor split the air on that bright, calm day in Cape Cod Bay off Provincetown’s Wood End Lighthouse. The V-shaped blow is not visible because the whale is positioned broadside to us. Most baleen whales have narrower spouts. With no dorsal fin and a brief glimpse of broad flukes—the whale’s tail—confirms the presence of a right whale, approximately 50 feet long.

Right whales are so rare that whale-watching vessels must stay at least 500 yards, or 1,500 feet, away so as not to disturb them. Right whales are like icebergs in freshwater, with most of their bodies hidden underwater. We watched the magnificent mammals from a distance.

Two right whales worked the shore along Herring Cove. Herring gulls showed no interest in the whales as they followed the fishing boat, heading for the harbor with the morning’s catch. Right whales eat zooplankton, straining small animals that drift in the water column with six-foot-long cartilage plates hanging down from the roof of the whale’s mouth. Hairs on baleen form a fine mesh that traps zooplankton inside, where the whale’s tongue, the size of a BMW Smart car, swipes and swallows.

A pair of right whales swim in synchronization, turning and rolling onto their right side to elevate the left side of their flukes above the water. A third whale follows closely behind the twisting whales.

Today, the whales are likely eating shoals of Calanus copepods that are corralled between them and the steeply rising shore. We saw between 12 and 17 right whales from Race Point, with its lighthouse, to Long Point, which has a lighthouse at the tip of the sandy finger at the end of the raised arm known as Cape Cod.

Further offshore from Herring Cove, a slim, long whale with a sharply curved dorsal fin blows, wheels, and dives. With many decades of experience, the whale-watch boat captain maneuvers closer and stops the engine as a second sei whale surfaces. Reaching as much as 60 feet, sei whales are the third largest whale in the world, preceded by blue and fin whales. Sei is Norwegian for pollack fish, as they were often seen together. 

The two dark, bluish-gray whales settle beneath the water beside the boat, the white of their undersides visible as they roll onto their sides. The roqual grooves along their pleated chin and cheeks distend. Still in the water, these whales let the plankton float into their mouths, or so we think, as we cannot see any plankton in the dark waters. They rose to breathe after a few minutes, which seemed to our astonishment like an eternity.

The first humpback whales of the season are found north of Race Point. Low in the water, they appear to be lounging about, perhaps taking it easy after a morning of feeding on sand lance. Last week, I found the pencil-thin fish on the Herring Cove beach, likely dropped by a gull. 

A humpback whale lies below the surface with its blowholes and dorsal fin above the water. To the right, a second whale stirs the water that laps over its back. 

The boat floats by the two humpback whales. Looking through the water, we see the whale’s 15-foot-long white flipper.  The scientific name for humpback whales is Megaptera novaeangliae, meaning large-winged New Englander.

We are startled to see a second flipper looming white beneath the whale. A third whale is stealthily poised directly below the whale on the surface.  When we saw two whales on the surface, there were really four humpbacks, surfacing two by two.

Later, all four whales were on the surface nearly at once. One rolled on its side to reach an enormous flipper to the sky. The narrator assured us that the whale was not waving. Whales slap the water to communicate with more distant whales, but there were no slapping sounds today.     

The whales slowly drifted beneath our vessel, revealing their entire outlines from above. Here, the tail fluke can be seen while the head and flippers are on the other side of the boat. The whales moved beneath us, from left to right and then from right to left, four times!

Finally, a humpback whale lifted its tail before diving. The black and white pattern on the underside was recognized as belonging to the female humpback named Habanero for the appearance of a chili pepper mark. Habanero is well known to the Dolphin Fleet of whale watch vessels. Habanero was observed with a calf in September 2012.  A second humpback was identified as Candlestick. The other two humpbacks never showed their tails.

Returning to the harbor, the right whales continued to forage along the shoreline. These whales are called urban whales because they come near our urban shores more often than others. Right whales do not migrate, except for females that give birth off Savannah and Jacksonville. The newborns have little blubber and require warm water. However, these clear waters offer little food. Therefore, right whales travel to Cape Cod Bay for the abundant shoals of zooplankton. They may stay for six weeks before spreading out across the North Atlantic.

Lobstermen do not trap during April and May along Massachusetts’ sandy shores and boat traffic consists of smaller vessels alert to right whales. The greatest threat to right whale survival is the diminishing availability of food. Our pollutants have caused phytoplankton productivity to drop by 60% since 2000. Copepods now have less fat content, requiring whales to consume more to obtain the same nutritional value.  

What we are doing to the land is harmful. We have crossed a tipping point by removing vegetation and soil, which hard surfaces and urbanization have replaced. There are cascading negative consequences. Boston’s annual rainfall is a steady 46.4 inches a year, yet, destructive stormwater and combined sewer overflows are rising because we have removed the vegetation and the soil carbon sponge.

Water that once soaked into the ground now washes across heat islands. It warms up and transports heat to the ocean. The year 2023 was not an exceptionally hot summer for Boston but it was the wettest summer since 1955. This resulted in a record warming of the Gulf of Maine surface waters nearest to Boston. While 2021 was Boston’s hottest summer, the surface ocean water did not experience significant warming.

Nutrients spilled into the sea fuel harmful algal blooms and ocean dead zones.  The ten-fold increase in the use of the herbicide Roundup since 1996, when Monsanto developed crops resistant to glyphosate, is likely more than coincidental to the loss of phytoplankton.

The solution to the threat to the ocean ecosystems on which whales depend lies on land. Land should be granted the right to retain the rainwater that falls upon it. Developers should not be permitted to profit from their constructions while leaving the municipality responsible for managing increased stormwater, likely leaving people in the flood zone standing in CSO sewage. 

The dry land heats up worsening climate change when developers starve the land of water.  Property owners must instead slow water down, return it to the ground where plants may draw to photosynthesize during the dry season, where groundwater may recharge rivers, and with water in the ground to prevent forest fires. Let’s improve the whale’s marine ecosystem with no more pollution, stormwater damage, and ocean heating from the land.

Returning past Race Point, a right whale raised its head high out of the water. Gray baleen plates hung beneath a white, encrusted black upper lip. In doing so, I don’t know what advantage was gained by the whale. I took it as a smile, as my smile was no less broad.

Nearly fifty years ago, on April 15, 1976, I was on the first Dolphin Fleet whale watch. We saw right whales and a humpback whale that the boat captain’s son would later name Salt when he became the boat captain. Since then, Salt has birthed 12 calves and is the grandmother of seven more humpback whales. There were then estimated to be 350 right whales. Today’s estimate is 372 whales, not including the ten calves born last winter.

I was on the first commercial whale watch because two summers earlier, I was alone on the deck of a 27-foot sailboat, south of Seguin Light off the coast of Maine. A right whale surfaced next to the boat. I babbled, having never imagined that something alive could be the size of a sandbar. The whale left only a circular slick spot on the water for the rest of the crew to see.

We are fortunate to be in the company of whales, which grace our sandy shores for about six weeks in spring. The loss of vegetation and soil on our properties and in neighborhoods is harming the marine ecosystem on which right whales depend to break their winter fast. To ensure future generations can share the ocean with a burgeoning right whale population, we must increase the carbon sponge on our land and stop stormwater runoff.  

Breathe. Wheel. Flukes up. Dive. Swim on, whales! 

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Dr. Rob Moir is a nationally recognized and award-winning environmentalist. He is the president and executive director of the Ocean River Institute, a nonprofit based in Cambridge, MA, that provides expertise, services, resources, and information not readily available on a localized level to support the efforts of environmental organizations. Please visit www.oceanriver.org for more information.

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More from Dr. Rob Moir

• Methane-Eating Bacteria & Archaea Saving Earth from the Ravages of Climate Change (and cattle burps)
• The Sultans of Swag Versus Looking at Clouds from Both Sides Now
• Restoring The Climate with Native Plants and Deeper Soils
• Hope for Right Whales
• Cooling the Gulf of Maine Surface Ocean Waters
• Touch the Earth Lightly, Use the Earth Gently
• Easter Island, Hard Work & Good Cheer for a Changing Climate-Challenged World
• Cooling Our Planet: New England’s Battle with Climate Change
• Land & Sea Change for Earth Day, Expanding The Climate Change Narrative
• The Earth and Three Blinkered Scientists
• Fallen Forests and Rising Ocean Fury
• What If There Was a Right Whale National Marine Sanctuary?
• Atlantic Ocean off Florida Spawns a Giant Sargassum Blob Due to Climate Change & Nutrient Pollution
• Emerald Bracelets to Solve Three of the World’s Greatest Environmental Problems
• Slowing Water for Greener Neighborhoods
• Put Down the Federal Stick to Build a Greener Future
• Of Mousy & Elephantine Cycles, Managing The Climate Crisis After Glasgow COP26
• Melting Greenland Ice Sheet, Sea Ice Formation, and the Flow of The Gulf Stream
• A Whale of a Pattern of Thought and Organizing Principle for Community-Based Environmental Management

A sunny day, clear skies, and warm sands. Relaxing at the beach can put one at ease and take all the troubles away. This picture asks a darker question: How much plastic can you find? During a beach cleanup, one group of volunteers collected two, one-gallon buckets weighing in at 20 pounds total. The majority of the culprits consisted of small plastic pieces (94 pieces smaller than an inch) and plastic bottle caps (42 pieces). Plastic entangled in seaweed and a nearby road means increased pollution heading out to sea. Those were just the plastics seen with the naked eye. What you think is sand could actually be bits of broken down plastic.

Most plastics have a significantly short time being used compared to how long they take to break down. A takeaway cup from our favorite coffee shops can take 30 years to break down, but that does not mean it goes away completely. They break down into smaller fragments and leach into our waterways. Microbeads were a hit with hygiene products, especially exfoliating face cleansers. Every day, people wash with face wash or exfoliating hand soap. The small plastic beads have a use for a minute or two before being washed down the drain. Water treatment plants only catch so much, with as much as 170,900 particles per kilogram reported in sewer sludge. Sewer sludge is a byproduct of waste treatment, consisting of semi-solid organic matter such as food waste, human waste, and contaminants. Sludge can be used in agriculture, meaning microplastics in sludge enter the environment. What does not end up in sludge goes into the water. Microbeads from cosmetics and skin care products slip through the treatment plants’ filters and make their way to the nearest outsource: ponds, lakes, and streams. Commercial and recreational fishing are also large contributors to plastic pollution in the ocean. Nylon nets and fishing line break or are improperly disposed of, increasing the chances of them being washed out to sea with the incoming tide.

The macro- and micro-plastics that do not end up back on land are swept away by the ocean currents. The plastic gets caught in the middle of oceanic gyres, or large rotating currents, and floats together to create patches of plastic ‘land’. There are five major gyres: northern and southern Pacific Ocean, northern and southern Atlantic Ocean, and Indian Ocean. They are located at the furthest points between land masses and are responsible for churning the ocean, making sure water flows across the globe. The Great Pacific Garbage Patch, located between the Americas and Asia, has the highest concentration of plastic on Earth, measuring 1.6 million square kilometers as of 2021. Ocean currents meet and create a self-rotating system where warm water meets cold water. These currents carry buoyant materials with them, which get trapped in the gyre. Once there, both macro- and micro-plastics sit static, degrading over time from the sun’s heat which introduces chemicals to the water and increases chances of ingestion. Marine animals not only eat plastic, but get trapped in nets, bags, and other plastic pieces floating loosely on these masses. Entanglement of marine mammals can alter behavioral characteristics, like decreased success with foraging and limiting mobility, or cause physical stress, causing abrasions and asphyxiation. If the animal is unable to untangle itself, it will grow with the plastic around them which leads to increased stress and mortality.

Macro- and micro-plastics in water systems are mistaken for food throughout the trophic levels. Located at the bottom of the food web are zooplankton. They mistake microplastic as food items and consume them, which then are eaten by fish and crustaceans. Larger predators consume their prey items until there is nowhere left to go. This causes harm to multiple species since plastic uptake accumulates through the trophic levels, or where an organism is in the food chain like in Figure 3. Research observed an equal amount of microplastic intake compared to food items in cod located in northern Alaska. The cod are not getting the nutrients they need to survive, leading to decreased health, blocked intestinal systems, and ultimately increased mortalities. For animals who rely on cod to meet their dietary and nutritional needs, there is a lack of nourishment if the cod only eats plastic. This is such a common phenomenon that researchers now take plastic into consideration when building food webs, introducing new systems solely based on plastic movement through the ecosystem. Moving up the food web, marine birds are affected by microplastics as they eat fish and use them to feed their young. Like fish, birds can also mistake plastic pieces on the beach as prey. Marine birds take in food near the ocean’s surface, and studies dating back as far as the 1960s have shown plastic in their intestinal tracts. A study in 1969 documented stomach contents of 100 Laysan albatross (Diomedia immutabilis) carcasses. Approximately 94% of the objects were buoyant, with 30% being documented as plastic. In the span of 50 years, however, increased plastic means increased consumption and more species affected.

While humans do not consider themselves animals, they are part of the same food web all wildlife partakes in. Humans are high in the food chain, farming fish in artificial ponds similar to how cows are farmed for beef; this action is referred to as aquaculture. Aquatic food items are diet staples for some cultures, and tracing plastic through the food chain can help us find which, if any, specific marine species are microplastic sources. On small islands, humans use the soil itself as food, including it in spices, marinades, and bread. A study conducted in 2022 observed plastic in all soil samples on the island of Hormoz, located close to Iran. A significant amount of these plastics were fibrous materials that came from local or tourist clothing.

Single-use plastics break down over time, allowing microplastics to seep into our bodies and our ecosystems. Reusing plastic containers and bottles is harmful to a person’s health. The amount of microplastics in our waterways makes the simple act of consuming salt or drinking water from the tap hazardous, increasing one’s plastic intake. Research shows a single person ingests as much as millions of microplastics in a year, and a study conducted in 2021 found microplastics, a completely man-made material, inside women’s placentas. The plastics were linked to dyes, colorants, and stains that are found in finger paints, clothing, and air fresheners. We are contaminated before we are even born. Once inside the body, plastics break down and become part of the system, inhibiting metabolism and increasing obesity risk.

Demand for plastic has been steadily rising across the globe since its creation in 1907. From the smallest creeks to the largest oceans, plastic is found in all water bodies. However, we see little improvement in recycling methods. Each type of plastic may require a different way to recycle it due to its chemical makeup. It is important we work more efficiently and effectively to control our plastic pollution. Increasing recycling centers as well as the efficiency of existing centers can decrease microplastic pollution. Organizations like Alliance for the Great Lakes can help clean up plastics already on coastlines and beaches. Ocean Cleanup, a nonprofit organization, uses metal grates to catch debris in rivers, as well as patrol with nets in the ocean to catch stray rubbish. However, it is up to the individual to take the initiative as well. Whether it is a park, beach, or shopping mall, it is important to dispose of rubbish appropriately. Even if it is not yours, it would help the environment if you took it with you to throw it away in the proper receptacles. We must all do our part to keep the Earth plastic-free.

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About the Author
Sara Dzialowy is an Aquarist Intern at OdySea Aquarium and a Master’s student in the Art of Biology through Project Dragonfly at Miami University-Ohio and Brookfield Zoo. With a focus on aquatic conservation and public education, she is passionate about inspiring others to protect marine life.

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